Immunology: Lymphoid Structures Flashcards
A young man contracts lymphogranuloma venereum as a result of unprotected sex. Which 3 lymph node clusters may exhibit pathologic involvement?
External iliac, internal iliac, superficial inguinal (commonly affected by sexually transmitted infections)
A patient in the ED undergoes an abdominal CT scan for evaluation of abdominal pain. Enlarged para-aortic lymph nodes are discovered. What diagnosis do you suspect?
A metastatic malignancy (particularly of the testes/ovaries, kidneys, or uterus)
A 17-year-old patient presents with a sore throat. A heterophile antibody test is positive. Which lymph node clusters may become enlarged?
Cervical and supraclavicular (which drain lymph from the head and neck, as in infectious mononucleosis)
A 2-month-old patient with DiGeorge syndrome lacks a developed thymus. What immune cell would you expect to be dysfunctional?
T cells (recall that the function of the Thymus is T-cell maturation)
A man with celiac sprue confined to the upper duodenum has a CT scan done to evaluate worsening abdominal pain. Imaging is likely to show enlargement of which lymph node cluster?
Celiac (which drains lymph from the foregut, including the upper duodenum and the associated digestive organs)
What is the function of the secondary immune system organs?
They allow immune cells to interact with antigens
A patient with sickle cell disease presents with fulminant meningococcemia. How did this most likely occur?
As a result of splenic dysfunction (decreased IgM, decreased complement activation, and decreased C3b opsonization lead to greater susceptibility to encapsulated organisms)
A patient has acute bacterial prostatitis complicated by abscess formation. Which lymph node cluster is likely to be enlarged?
Internal Iliac (which drains lymph from the bladder, cervix, prostate, middle third of the vagina, and lower rectum to the anal canal above the pectinate line)
In which region of the lymph node do B cells proliferate?
Follicle
To which lymph node cluster would an adenocarcinoma of the ascending colon likely metastasize first?
Superior mesenteric (which drains lymph from the proximal colon extending to the splenic flexure)
What 4 paraneoplastic syndromes are clasically associated with thymomas?
Superior vena cava syndrome, myasthenia gravis, pure red cell aplasia, and Good syndrome
A 35-year-old woman experiences progressive weakness of the ocular muscles and extremities. These symptoms worsen toward evening. Which mediastinal organ may be abnormal?
The thymus (can be enlarged or contain a thymoma in association with myasthenia gravis)
A patient’s blood work reveals thrombocytosis and lymphocytosis. A peripheral blood smear shows nuclear remnants and target cells. Most likely cause of these findings?
Splenectomy (nuclear remnants are probably Howell-Jolly bodies)
Which lymph node cluster is likely to be enlarged in a patient with sarcoidosis?
Hilar (which drains lymph from the lungs and is commonly enlarged in granulomatous diseases)
Which histologic section of the thymus contains immature T cells?
The cortex, which is dense with immature T cells
A lymph node has both primary and secondary follicles in its outer cortex. What is the difference between them?
Primary follicles are dormant and dense; secondary follicles are active and have pale germinal centers
A patient develops cellulitis of the medial aspect of the leg after a “spider bite.” Which lymph node cluster may become enlarged?
Superficial inguinal (which drains lymph from the skin below the umbilicus except for the popliteal region)
A child with Kawasaki disease may have significant lymphadenopathy in what area of the body?
Cervical (head and neck)
What is the region immediately surrounding the germinal center in a secondary follicle?
The mantle zone
A patient is found to have an invasive duodenal tumor on endoscopic examination. Which 2 lymph node clusters should be assessed for metastasis?
Celiac and superior mesenteric (which drain lymph from the upper duodenum and lower duodenum, respectively)
What are the 2 primary immune system organs?
Bone marrow and thymus
What structure surrounds the thymus?
A capsule (as the thymus, like the lymph nodes and spleen, is encapsulated)
In which histologic section of the spleen are T and B cells found?
White pulp
A patient develops thrombosis at the junction of the left subclavian and internal jugular veins. Where in the body might you see any resulting lymphedema?
Entire body except for right half above the diaphragm (drained by right lymphatic duct), as flow in the thoracic duct is probably impaired
The medulla of the lymph node contains medullary cords and sinuses. What 2 types of cells are found in the sinuses?
Macrophages and reticular cells
A patient with diabetes has a painful abscess on the dorsolateral aspect of his right foot. Which lymph node cluster is likely to become enlarged?
Popliteal (which drains lymph from the posterior calf and dorsolateral foot)
What is the function of the marginal zone in the spleen?
This is the location where antigen-presenting cells (APCs) capture antigens for later recognition by lymphocytes
On microscopic examination, a lymph node is found to contain large follicles with pale centers. What kind of follicles are these?
Secondary follicles, which have active (pale) germinal centers
A patient has significantly enlarged superficial inguinal lymph nodes as determined by a CT scan. Where should the physical exam be focused to find the cause?
The scrotum or vulva, anal canal below the pectinate line, and subumbilical skin except popliteal area (all of which are drained by the superficial inguinal lymph nodes)
In which section of the lymph node are T cells housed?
Paracortex
